The goal of this project is to elucidate the mechanism by which human red blood cell membranes facilitate the diffusion of two distinctly different types of molecules: anions and nucleosides. The main line of work emphasizes the identification, isolation, chemical characterization and reconstitution of the critical membrane components of the two transport systems. The ultimate goal is to provide functional isolated systems in which transport processes can be dissected out into molecular events with the aid of a battery of physicochemical techniques which include fluorescence, ESR and NMR spectroscopy. BIBLIOGRAPHIC REFERENCES: Cabantchik, Z.I., Wolosin, J.M., Ginsburg, H. and Zemel, O.: Structural and functional properties of the anion transport system isolated from human erythrocyte membranes. In "Biochemistry of Membrane Transport," G. Senenza and E. Carafoli, eds., pp. 328-345, 1977. Rothstein, A., Knauf, P.A. and Cabantchik, Z.I.: Naptaurine, a photoaffinity probe for the anion transport system of the red blood cell." In "Biochemistry of Membrane Transport." G. Semenza and E. Carafoli, eds., pp. 316-327, 1977.